Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2010-02-18
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
8 Pages, 7 Figures ApJ, In Press
Scientific paper
We analyze a suite of global magnetohydrodynamic (MHD) accretion disk simulations in order to determine whether scaling laws for turbulence driven by the magnetorotational instability, discovered via local shearing box studies, are globally robust. The simulations model geometrically-thin disks with zero net magnetic flux and no explicit resistivity or viscosity. We show that the local Maxwell stress is correlated with the self-generated local vertical magnetic field in a manner that is similar to that found in local simulations. Moreover, local patches of vertical field are strong enough to stimulate and control the strength of angular momentum transport across much of the disk. We demonstrate the importance of magnetic linkages (through the low-density corona) between different regions of the disk in determining the local field, and suggest a new convergence requirement for global simulations -- the vertical extent of the corona must be fully captured and resolved. Finally, we examine the temporal convergence of the average stress, and show that an initial long-term secular drift in the local flux-stress relation dies away on a time scale that is consistent with turbulent mixing of the initial magnetic field.
Armitage Philip J.
Reynolds Christopher S.
Sorathia Kareem A.
No associations
LandOfFree
Connections Between Local and Global Turbulence in Accretion Disks does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Connections Between Local and Global Turbulence in Accretion Disks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Connections Between Local and Global Turbulence in Accretion Disks will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-362449